Source: Mailed anthrax was not old

From Kelli ArenaCNN Washington Bureau

WASHINGTON (CNN) --A senior government official who wished not to be identified told CNN Saturday that testing has determined the deadly anthrax mailed to various places last fall was no more than two years old.

This discovery lends credence to the theory that whoever mailed the finely milled anthrax spores -- known to be of the Ames strain -- has a current connection to a sophisticated laboratory.

Investigators have long believed the suspect possessed a sophisticated knowledge of anthrax and a high level of training.

Currently, many scientists who are knowledgeable about anthrax are taking polygraph tests and undergoing interviews as investigators try to uncover suspects.

Still, investigators say they are far from solving the mystery of who sent the deadly spores.

Five people died last fall after anthrax-laced letters were sent through the mail to members of Congress in Washington and to television network offices in New York.

Along the way, anthrax spores leaking from the letters contaminated post office buildings in Washington and New Jersey.

Two Washington postal workers died of inhaled anthrax, as did two women thought to have been infected from the mail. A Florida employee of a national tabloid also died of inhaled anthrax, and though no contaminated letter was found in connection with his death, investigators found traces of anthrax in the company's mailroom.

At least 13 people developed either skin or respiratory anthrax, but they have recovered.

The strain of anthrax found in letters mailed to U.S. Sens. Tom Daschle, D-South Dakota, and Patrick Leahy, D-Vermont, is called Ames, after the Iowa city where researchers first isolated it.